scholarly journals SLC22 Transporters in the Fly Renal System Regulate Response to Oxidative Stress In Vivo

2021 ◽  
Vol 22 (24) ◽  
pp. 13407
Author(s):  
Patrick Zhang ◽  
Priti Azad ◽  
Darcy C. Engelhart ◽  
Gabriel G. Haddad ◽  
Sanjay K. Nigam
Keyword(s):  
Oxidative Stress ◽  
Fat Body ◽  
Organic Anion ◽  
Malpighian Tubule ◽  
Human Kidney ◽  
Organic Anion Transporter ◽  
In Vivo Studies ◽  
Anion Transporter ◽  
Renal System

Several SLC22 transporters in the human kidney and other tissues are thought to regulate endogenous small antioxidant molecules such as uric acid, ergothioneine, carnitine, and carnitine derivatives. These transporters include those from the organic anion transporter (OAT), OCTN/OCTN-related, and organic cation transporter (OCT) subgroups. In mammals, it has been difficult to show a clear in vivo role for these transporters during oxidative stress. Ubiquitous knockdowns of related Drosophila SLC22s—including transporters homologous to those previously identified by us in mammals such as the “Fly-Like Putative Transporters” FLIPT1 (SLC22A15) and FLIPT2 (SLC22A16)—have shown modest protection against oxidative stress. However, these fly transporters tend to be broadly expressed, and it is unclear if there is an organ in which their expression is critical. Using two tissue-selective knockdown strategies, we were able to demonstrate much greater and longer protection from oxidative stress compared to previous whole fly knockdowns as well as both parent and WT strains (CG6126: p < 0.001, CG4630: p < 0.01, CG16727: p < 0.0001 and CG6006: p < 0.01). Expression in the Malpighian tubule and likely other tissues as well (e.g., gut, fat body, nervous system) appear critical for managing oxidative stress. These four Drosophila SLC22 genes are similar to human SLC22 transporters (CG6126: SLC22A16, CG16727: SLC22A7, CG4630: SLC22A3, and CG6006: SLC22A1, SLC22A2, SLC22A3, SLC22A6, SLC22A7, SLC22A8, SLC22A11, SLC22A12 (URAT1), SLC22A13, SLC22A14)—many of which are highly expressed in the kidney. Consistent with the Remote Sensing and Signaling Theory, this indicates an important in vivo role in the oxidative stress response for multiple SLC22 transporters within the fly renal system, perhaps through interaction with SLC22 counterparts in non-renal tissues. We also note that many of the human relatives are well-known drug transporters. Our work not only indicates the importance of SLC22 transporters in the fly renal system but also sets the stage for in vivo studies by examining their role in mammalian oxidative stress and organ crosstalk.

Transport of cimetidine by flounder and human renal organic anion transporter 1

2003 ◽  
Vol 284 (3) ◽  
pp. F503-F509 ◽  
Author(s):  
Birgitta C. Burckhardt ◽  
Stefan Brai ◽  
Sönke Wallis ◽  
Wolfgang Krick ◽  
Natascha A. Wolff ◽  
...  
Keyword(s):  
Organic Anion ◽  
Human Kidney ◽  
Organic Anion Transporter ◽  
In Vivo Studies ◽  
Xenopus Laevis Oocytes ◽  
Organic Anion Transporters ◽  
Anion Transporters ◽  
Anion Transporter ◽  
Inward Currents

The H2-receptor antagonist cimetidine is efficiently excreted by the kidneys. In vivo studies indicated an interaction of cimetidine not only with transporters for basolateral uptake of organic cations but also with those involved in excretion of organic anions. We therefore tested cimetidine as a possible substrate of the organic anion transporters cloned from winter flounder (fROAT) and from human kidney (hOAT1). Uptake of [3H]cimetidine into fROAT-expressing Xenopus laevis oocytes exceeded uptake into control oocytes. At −60-mV clamp potential, 1 mM cimetidine induced an inward current, which was smaller than that elicited by 0.1 mM PAH. Cimetidine concentrations exceeding 0.1 mM decreased PAH-induced inward currents, indicating interaction with the same transporter. At pH 6.6, no current was seen with 0.1 mM cimetidine, whereas at pH 8.6 a current was readily detectable, suggesting preferential translocation of uncharged cimetidine by fROAT. Oocytes expressing hOAT1 also showed [3H]cimetidine uptake. These data reveal cimetidine as a substrate for fROAT/hOAT1 and suggest that organic anion transporters contribute to cimetidine excretion in proximal tubules.

Characterization of the Uptake of Organic Anion Transporter (OAT) 1 and OAT3 Substrates by Human Kidney Slices

2007 ◽  
Vol 321 (1) ◽  
pp. 362-369 ◽  
Author(s):  
Yoshitane Nozaki ◽  
Hiroyuki Kusuhara ◽  
Tsunenori Kondo ◽  
Maki Hasegawa ◽  
Yoshiyuki Shiroyanagi ◽  
...  
Keyword(s):  
Organic Anion ◽  
Human Kidney ◽  
Organic Anion Transporter ◽  
Kidney Slices ◽  
Anion Transporter

scholarly journals Application of a PBPK Model of Rivaroxaban to Prospective Simulations of Drug-Drug-Disease Interactions with Protein Kinase Inhibitors in CA-VTE

2021 ◽  
Author(s):  
Eleanor Jing Yi Cheong ◽  
Daniel Zhi Wei Ng ◽  
Sheng Yuan Chin ◽  
Ziteng Wang ◽  
Eric Chun Yong Chan
Keyword(s):  
Protein Kinase ◽  
Kinase Inhibitors ◽  
Pbpk Model ◽  
Organic Anion ◽  
Protein Kinase Inhibitors ◽  
Organic Anion Transporter ◽  
Pbpk Modelling ◽  
Anion Transporter

Background and Purpose Rivaroxaban is emerging as a viable anticoagulant for the pharmacological management of cancer associated venous thromboembolism (CA-VTE). Being eliminated via CYP3A4/2J2-mediated metabolism and organic anion transporter 3 (OAT3)/P-glycoprotein-mediated renal secretion, rivaroxaban is susceptible to drug-drug interactions (DDIs) with protein kinase inhibitors (PKIs), erlotinib and nilotinib. Physiologically based pharmacokinetic (PBPK) modelling was applied to interrogate the DDIs for dose adjustment of rivaroxaban in CA-VTE. Experimental Approach The inhibitory potencies of erlotinib and nilotinib on CYP3A4/2J2-mediated metabolism of rivaroxaban were characterized. Using prototypical OAT3 inhibitor ketoconazole, in vitro OAT3 inhibition assays were optimized to ascertain the in vivo relevance of derived inhibitory constants (K). DDIs between rivaroxaban and erlotinib or nilotinib were investigated using iteratively verified PBPK model. Key Results Mechanism-based inactivation (MBI) of CYP3A4-mediated rivaroxaban metabolism by both PKIs and MBI of CYP2J2 by erlotinib were established. The importance of substrate specificity and nonspecific binding to derive OAT3-inhibitory K values of ketoconazole and nilotinib for the accurate prediction of DDIs was illustrated. When simulated rivaroxaban exposure variations with concomitant erlotinib and nilotinib therapy were evaluated using published dose-exposure equivalence metrics and bleeding risk analyses, dose reductions from 20 mg to 15 mg and 10 mg in normal and mild renal dysfunction, respectively, were warranted. Conclusion and Implications We established the PBPK-DDI platform to prospectively interrogate and manage clinically relevant interactions between rivaroxaban and PKIs in patients with underlying renal impairment. Rational dose adjustments were proposed, attesting to the capacity of PBPK modelling in facilitating precision medicine.

Inhibition of initial transport rate of basolateral organic anion carrier in renal PT by BK and phenylephrine

1999 ◽  
Vol 277 (2) ◽  
pp. F251-F256 ◽  
Author(s):  
Michael Gekle ◽  
Sigrid Mildenberger ◽  
Christoph Sauvant ◽  
Dallas Bednarczyk ◽  
Stephen H. Wright ◽  
...  
Keyword(s):  
Direct Action ◽  
Organic Anion ◽  
Specific Inhibitor ◽  
Peptide Hormone ◽  
Organic Anion Transporter ◽  
Epifluorescence Microscopy ◽  
Anion Transporter ◽  
Initial Uptake Rate ◽  
Continuous Presence

The effect of ligands for phospholipase C-coupled receptors and of protein kinase C (PKC) stimulation with phorbol ester [phorbol 12-myristate 13-acetate (PMA)] or 1,2-dioctanoyl- sn-glycerol on the activity of the basolateral organic anion transporter (OAT) in S2 segments of single, nonperfused rabbit proximal tubules (PT) was measured with the use of fluorescein and epifluorescence microscopy. The initial uptake rate (25 s, OAT activity) was measured in real time by using conditions similar to those found in vivo. Stimulation of PKC with PMA or 1,2-dioctanoyl- sn-glycerol led to an inhibition of OAT activity, which could be prevented by 10−7 mol/l of the PKC-specific inhibitor bisindolylmaleimide. The α1-receptor agonist phenylephrine as well as the peptide hormone bradykinin induced a reversible decrease of OAT activity, which was prevented by bisindolylmaleimide. The observed effect was not due to a decrease in the concentration of the counterion α-ketoglutarate or to impaired α-ketoglutarate recycling, because it was unchanged in the continuous presence of α-ketoglutarate or methyl succinate. We conclude that physiological stimuli can inhibit the activity of OAT in rabbit PT via PKC. The effect is not mediated by alterations in counterion availability but by a direct action on the OAT.

scholarly journals Acute Exposure to Indoxyl Sulfate Impairs Endothelium-Dependent Vasorelaxation in Rat Aorta

2019 ◽  
Vol 20 (2) ◽  
pp. 338 ◽  
Author(s):  
Takayuki Matsumoto ◽  
Keisuke Takayanagi ◽  
Mihoka Kojima ◽  
Kumiko Taguchi ◽  
Tsuneo Kobayashi
Keyword(s):  
Oxidative Stress ◽  
Gut Microbiota ◽  
Nadph Oxidase ◽  
Vascular Function ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Indoxyl Sulfate ◽  
Transient Receptor Potential Vanilloid ◽  
Ionophore A23187 ◽  
Anion Transporter

Gut microbiota are emerging as potential contributors to the regulation of host homeostasis. Dysbiosis of the gut microbiota associated with increased intestinal permeability facilitates the passage of endotoxins and other microbial products, including indoxyl sulfate in the circulation. Although an emerging body of evidence has suggested that indoxyl sulfate is a key substance for the development of chronic kidney disease, few studies have investigated the direct association of indoxyl sulfate with vascular function. We hypothesized that indoxyl sulfate adversely affects vascular function. Aortas isolated from male Wistar rat were examined in the presence or absence of indoxyl sulfate to assess the vascular function, including vasorelaxation and vasocontraction. Indoxyl sulfate (vs. vehicle) (1) decreased vasorelaxation induced by acetylcholine (ACh) but not by sodium nitroprusside; (2) had no significant alterations of noradrenaline-induced vasocontraction in the absence and presence of endothelium; (3) decreased adenylyl cyclase activator (forskolin)-induced vasorelaxation, while such a difference was eliminated by endothelial denudation; and (4) decreased vasorelaxations induced by calcium ionophore (A23187) and transient receptor potential vanilloid 4 agonist (GSK1016790A). The indoxyl sulfate-induced decrease in the vasorelaxations induced by ACh and A23187 increased by cell-permeant superoxide dismutase or by organic anion transporter inhibitor. However, apocynin, an inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, had no effects on vasorelaxations induced by ACh, A23187, forskolin, and GSK1016790A in the presence of indoxyl sulfate. These results suggest that indoxyl sulfate directly affects the vascular function, particularly, endothelium-dependent vasorelaxation, and this effect may be attributable to increased oxidative stress after cell transportion via organic anion transporter, and such increased oxidative stress may not be attributable to activation of NADPH oxidase activation.

scholarly journals In vivo Cisplatin Resistance Depending upon Canalicular Multispecific Organic Anion Transporter (cMOAT)

1999 ◽  
Vol 90 (10) ◽  
pp. 1171-1178 ◽  
Author(s):  
Tomoyoshi Minamino ◽  
Mitsuo Tamai ◽  
Yoshie Itoh ◽  
Yasuaki Tatsumi ◽  
Masaaki Nomura ◽  
...  
Keyword(s):  
Cisplatin Resistance ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Anion Transporter

scholarly journals Interactions of 172 plant extracts with human organic anion transporter 1 (SLC22A6) and 3 (SLC22A8): a study on herb-drug interactions

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3333 ◽  
Author(s):  
Hang Lu ◽  
Zhiqiang Lu ◽  
Xue Li ◽  
Gentao Li ◽  
Yilin Qiao ◽  
...  
Keyword(s):  
Drug Interactions ◽  
Plant Extracts ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Hek293 Cells ◽  
Pharmacokinetic Parameters ◽  
Renal Elimination ◽  
Juncus Effusus ◽  
Anion Transporter

BackgroundHerb-drug interactions (HDIs) resulting from concomitant use of herbal products with clinical drugs may cause adverse reactions. Organic anion transporter 1 (OAT1) and 3 (OAT3) are highly expressed in the kidney and play a key role in the renal elimination of substrate drugs. So far, little is known about the herbal extracts that could modulate OAT1 and OAT3 activities.MethodsHEK293 cells stably expressing human OAT1 (HEK-OAT1) and OAT3 (HEK-OAT3) were established and characterized. One hundred seventy-two extracts from 37 medicinal and economic plants were prepared. An initial concentration of 5 µg/ml for each extract was used to evaluate their effects on 6-carboxylfluorescein (6-CF) uptake in HEK-OAT1 and HEK-OAT3 cells. Concentration-dependent inhibition studies were conducted for those extracts with more than 50% inhibition to OAT1 and OAT3. The extract ofJuncus effusus, a well-known traditional Chinese medicine, was assessed for its effect on thein vivopharmacokinetic parameters of furosemide, a diuretic drug which is a known substrate of both OAT1 and OAT3.ResultsMore than 30% of the plant extracts at the concentration of 5 µg/ml showed strong inhibitory effect on the 6-CF uptake mediated by OAT1 (61 extracts) and OAT3 (55 extracts). Among them, three extracts for OAT1 and fourteen extracts for OAT3 were identified as strong inhibitors with IC50values being <5 µg/ml.Juncus effususshowed a strong inhibition to OAT3in vitro, and markedly altered thein vivopharmacokinetic parameters of furosemide in rats.ConclusionThe present study identified the potential interactions of medicinal and economic plants with human OAT1 and OAT3, which is helpful to predict and to avoid potential OAT1- and OAT3-mediated HDIs.

scholarly journals Cytotoxicity of Antiviral Nucleotides Adefovir and Cidofovir Is Induced by the Expression of Human Renal Organic Anion Transporter 1

2000 ◽  
Vol 11 (3) ◽  
pp. 383-393 ◽  
Author(s):  
EDMUND S. HO ◽  
DEBORAH C. LIN ◽  
DIRK B. MENDEL ◽  
TOMAS CIHLAR
Keyword(s):  
Organic Anion ◽  
Critical Role ◽  
Antiviral Agents ◽  
Chinese Hamster ◽  
Organic Anion Transporter ◽  
Nucleotide Analogs ◽  
Anion Transporter ◽  
Organ Specific

Abstract. The transport of organic anions in proximal convoluted tubules plays an essential role in the active secretion of a variety of small molecules by the kidney. In addition to other anionic substrates, the human renal organic anion transporter 1 (hOAT1) is capable of transporting the nucleotide analogs adefovir and cidofovir. To investigate the involvement of hOAT1 in the mechanism of nephrotoxicity associated with these two clinically important antiviral agents, Chinese hamster ovary (CHO) cells were stably transfected with hOAT1 cDNA. The resulting CHOhOAT cells showed probenecid-sensitive and pH-dependent uptake of p-aminohippurate (Km = 15.4 μM, Vmax = 20.6 pmol/106 cells · min), a prototypical organic anion substrate. In addition, the stably expressed hOAT1 mediated efficient transport of adefovir (Km = 23.8 μM, Vmax = 46.0 pmol/106 cells · min) and cidofovir (Km = 58.0 μM, Vmax = 103 pmol/106 cells · min) such that the levels of intracellular metabolites of both nucleotides were >100-fold higher in CHOhOAT cells than in parental CHO. Consequently, adefovir and cidofovir were approximately 500-fold and 400-fold more cytotoxic, respectively, in CHOhOAT cells compared to CHO. The cytotoxicity of both drugs in CHOhOAT cells was markedly reduced in the presence of hOAT1 inhibitors. The cyclic prodrug of cidofovir, which exhibits reduced in vivo nephrotoxicity, was a poor substrate for hOAT1 and showed only marginally increased cytotoxicity in CHOhOAT cells. In conclusion, these studies demonstrate that hOAT1 plays a critical role in the organ-specific toxicity of adefovir and cidofovir, and indicates that CHOhOAT cells may represent a useful in vitro model to investigate the potential nephrotoxicity of clinically relevant organic anion agents.

scholarly journals Mammalian colonocytes possess a carrier-mediated mechanism for uptake of vitamin B3 (niacin): studies utilizing human and mouse colonic preparations

2013 ◽  
Vol 305 (3) ◽  
pp. G207-G213 ◽  
Author(s):  
Jeyan S. Kumar ◽  
Veedamali S. Subramanian ◽  
Rubina Kapadia ◽  
Moti L. Kashyap ◽  
Hamid M. Said
Keyword(s):  
Nicotinic Acid ◽  
Large Intestine ◽  
Protein Tyrosine Kinase ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Vitamin B3 ◽  
Regulatory Pathways ◽  
Anion Transporter

Niacin (vitamin B3; nicotinic acid) plays an important role in maintaining redox state of cells and is obtained from endogenous and exogenous sources. The latter source has generally been assumed to be the dietary niacin, but another exogenous source that has been ignored is the niacin that is produced by the normal microflora of the large intestine. For this source of niacin to be bioavailable, it needs to be absorbed, but little is known about the ability of the large intestine to absorb niacin and the mechanism involved. Here we addressed these issues using the nontransformed human colonic epithelial NCM460 cells, native human colonic apical membrane vesicles (AMV) isolated from organ donors, and mouse colonic loops in vivo as models. Uptake of3H-nicotinic acid by NCM460 cells was: 1) acidic pH (but not Na+) dependent; 2) saturable (apparent Km= 2.5 ± 0.8 μM); 3) inhibited by unlabeled nicotinic acid, nicotinamide, and probenecid; 4) neither affected by other bacterially produced monocarboxylates, monocarboxylate transport inhibitor, or by substrates of the human organic anion transporter-10; 5) affected by modulators of the intracellular protein tyrosine kinase- and Ca2+-calmodulin-regulatory pathways; and 6) adaptively regulated by extracellular nicotinate level. Uptake of nicotinic acid by human colonic AMV in vitro and by mouse colonic loops in vivo was also carrier mediated. These findings report, for the first time, that mammalian colonocytes possess a high-affinity carrier-mediated mechanism for nicotinate uptake and show that the process is affected by intracellular and extracellular factors.

scholarly journals Involvement of Organic Anion Transporters in the Pharmacokinetics and Drug Interaction of Rosmarinic Acid

Pharmaceutics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 83
Author(s):  
Yun Ju Kang ◽  
Chul Haeng Lee ◽  
Soo-Jin Park ◽  
Hye Suk Lee ◽  
Min-Koo Choi ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Rosmarinic Acid ◽  
Renal Excretion ◽  
Organic Anion ◽  
Plasma Concentrations ◽  
Pharmacokinetic Interaction ◽  
Organic Anion Transporter ◽  
Hek293 Cells ◽  
Anion Transporter

We investigated the involvement of drug transporters in the pharmacokinetics of rosmarinic acid in rats as well as the transporter-mediated drug interaction potential of rosmarinic acid in HEK293 cells overexpressing clinically important solute carrier transporters and also in rats. Intravenously injected rosmarinic acid showed bi-exponential decay and unchanged rosmarinic acid was mainly eliminated by urinary excretion, suggesting the involvement of transporters in its renal excretion. Rosmarinic acid showed organic anion transporter (OAT)1-mediated active transport with a Km of 26.5 μM and a Vmax of 69.0 pmol/min in HEK293 cells overexpressing OAT1, and the plasma concentrations of rosmarinic acid were increased by the co-injection of probenecid because of decreased renal excretion due to OAT1 inhibition. Rosmarinic acid inhibited the transport activities of OAT1, OAT3, organic anion transporting polypeptide (OATP)1B1, and OATP1B3 with IC50 values of 60.6 μM, 1.52 μM, 74.8 μM, and 91.3 μM, respectively, and the inhibitory effect of rosmarinic acid on OAT3 transport activity caused an in vivo pharmacokinetic interaction with furosemide by inhibiting its renal excretion and by increasing its plasma concentration. In conclusion, OAT1 and OAT3 are the major transporters that may regulate the pharmacokinetic properties of rosmarinic acid and may cause herb-drug interactions with rosmarinic acid, although their clinical relevance awaits further evaluation.

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